BEGIN (include.latte) include ‘define.latte’
END (include.latte) include ‘define.latte’
BEGIN (include.latte) include #definetest if set(include.latte) block ‘definetest’ not defined
END (include.latte) include #definetest if set

END (include.latte) block content

I expected:

that with ‘includeblock’ only blocks where included, and not the text
outside blocks

that with ‘define’ the defined block could be rendered
with {include #blockname}

so the questions are:

in what ‘includeblock’ differs from ‘include’, and how it is meant
to be used?